Macro Root Flaw
Macroscopic root defects are poor geometries at the weld root, like incomplete penetration or incomplete fill. They compromise the static integrity of a single-sided weld.
Physicochemical Mechanism of Action
A macroscopic root defect forms when the steel is not fully penetrated during welding or the gap between the parts is not completely filled. This leads to inadequate joints at the weld root.
Metallurgical Relevance & Welding Risks
These defects can considerably reduce the mechanical properties of the weld, especially its stress limit and toughness. They raise the susceptibility to cracking and failure under load. A macroscopic root defect can also lead to uneven elongation and distortion of the parts.
Workshop Practice & Instructions
To avoid macroscopic root defects, it is crucial to run the weld correctly. That means setting the welding machine so the steel is fully penetrated and the gap between the parts is completely filled. The right setting depends on the material used and the desired joint thickness. It is also important to align and position the parts correctly before welding.